Survey Validity

Studies of surveys similar to the IYS that check substance use responses against actual drug tests have shown substantial validity. In addition, the patterns of use revealed by the IYS are consistent with other measures such as differential treatment rates for different substances. Although the survey provides valid statewide estimates of alcohol, tobacco, and other drug (ATOD) use, the data collection process does have limitations. Since the surveys are conducted in school settings, the sample does not include youth who are chronically absent, in alternative school settings, or are not enrolled in a school (including those who have dropped out of school). In addition, IYS survey administration is dependent on an individual school’s willingness to voluntarily participate. Finally, as with all self-report surveys, there is a possibility that respondents may not be truthful in their answers. Data collection processes are closely monitored to address these limitations whenever possible and to screen for inconsistencies in the self-report data.

Perhaps one of the most important things a school can do to ensure validity is to follow the survey administration instructions. Most importantly, the instructions highlight ways to make students comfortable with the fact that the survey will not be traced back to them. Click here to learn more about our survey content.

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About the Illinois Youth Survey

The Illinois Department of Human Services (IDHS) has funded the administration of the Illinois Youth Survey (IYS) biennially since 1993. The IYS is a self-report survey administered in school settings and is designed to gather information about a variety of health and social indicators including substance use patterns and attitudes of Illinois youth.